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Fencer Vulns
high 8.2

CVE-2026-64287 json

KVM: arm64: Bound used_lrs when flushing the pKVM hyp vCPU

published 2026-07-25 3 mo ago modified 2026-10-19 20 d ago also EUVD-2026-48999

cvss
8.2
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 7%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

KVM: arm64: Bound used_lrs when flushing the pKVM hyp vCPU

flush_hyp_vcpu() copies the host vGIC state into the hyp's private vCPU on every run. The vGIC list register save and restore use used_lrs as their loop bound and expect it to stay within the number of implemented list registers. While this is generally the case, flush_hyp_vcpu() copies vgic_v3 verbatim and does not enforce this, so a value provided by the host is used at EL2 to index vgic_lr[] and access ICH_LR<n>_EL2 (host -> EL2).

Fix by clamping used_lrs to the number of implemented list registers after the copy, as the trusted path already does in vgic_flush_lr_state(). The number of implemented list registers is constant after init, so it is replicated once from kvm_vgic_global_state.nr_lr into hyp_gicv3_nr_lr rather than read on every entry.

Patch / fix

  • Linux Linux 6.6.145, 6.12.97, 6.18.40, 7.1.4, 7.2
  • linux Debian 13 6.12.100-1
  • linux Debian 14 7.1.4-1
  • linux-6.12 Debian 12 6.12.100-1~deb12u1

debian advisories DEBIAN-CVE-2026-64287

  • linux Ubuntu 24.04 LTS 6.8.0-147.147
  • linux Ubuntu 26.04 LTS 7.0.0-31.31
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1067.70
  • linux-aws Ubuntu 26.04 LTS 7.0.0-1012.12
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1071.79
  • linux-gcp Ubuntu 26.04 LTS 7.0.0-1011.11
  • linux-gke Ubuntu 24.04 LTS 6.8.0-1066.74
  • linux-gke Ubuntu 26.04 LTS 7.0.0-1006.7

ubuntu advisories UBUNTU-CVE-2026-64287

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel RHEL 9 5.14.0-687.45.1.el9_8
  • rv RHEL 9 5.14.0-687.45.1.el9_8
  • perf RHEL 9 5.14.0-687.45.1.el9_8
  • rtla RHEL 9 5.14.0-687.45.1.el9_8
  • libperf RHEL 9 5.14.0-687.45.1.el9_8
  • kernel-rt RHEL 9 5.14.0-687.45.1.el9_8
  • kernel-64k RHEL 9 5.14.0-687.45.1.el9_8
  • kernel-core RHEL 9 5.14.0-687.45.1.el9_8

red hat advisories RHSA-2026:64808RHSA-2026:64775

  • kernel-64kb SLE Module for Basesystem 15 SP7 6.4.0-150700.53.81.1
  • kernel-syms SLE Module for Development Tools 15 SP7 6.4.0-150700.53.81.1
  • kernel-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.53.81.1
  • kernel-source SLE Module for Development Tools 15 SP7, SLE Module for Basesystem 15 SP7 6.4.0-150700.53.81.1
  • kernel-default SLE Workstation Extension 15 SP7, SLE Module for Legacy 15 SP7, SLE Module for Basesystem 15 SP7 +2 more 6.4.0-150700.53.81.1
  • kernel-zfcpdump SLE Module for Basesystem 15 SP7 6.4.0-150700.53.81.1
  • kernel-obs-build SLE Module for Development Tools 15 SP7 6.4.0-150700.53.81.1
  • kernel-default-base SLE Module for Basesystem 15 SP7 6.4.0-150700.53.81.1.150700.17.45.1

suse advisories SUSE-SU-2026:4254-1SUSE-SU-2026:23887-1SUSE-SU-2026:23902-1SUSE-SU-2026:23897-1SUSE-SU-2026:23881-1SUSE-SU-2026:4120-1

  • kernel-rt openSUSE Leap 16.0 6.12.0-160000.38.1
  • dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-64kb openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-syms openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-azure openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-source openSUSE Leap 16.0 6.12.0-160000.38.1
  • kernel-default openSUSE Leap 16.0 6.12.0-160000.38.1

opensuse advisories openSUSE-SU-2026:21910-1openSUSE-SU-2026:11476-1

  • kernel AlmaLinux 9 5.14.0-687.45.1.el9_8
  • rv AlmaLinux 9 5.14.0-687.45.1.el9_8
  • perf AlmaLinux 9 5.14.0-687.45.1.el9_8
  • rtla AlmaLinux 9 5.14.0-687.45.1.el9_8
  • libperf AlmaLinux 9 5.14.0-687.45.1.el9_8
  • kernel-rt AlmaLinux 9 5.14.0-687.45.1.el9_8
  • kernel-64k AlmaLinux 9 5.14.0-687.45.1.el9_8
  • kernel-core AlmaLinux 9 5.14.0-687.45.1.el9_8

almalinux advisories ALSA-2026:64808

  • kernel Rocky Linux 10 6.12.0-211.52.1.el10_2
  • kernel Rocky Linux 9 5.14.0-687.45.1.el9_8

rocky linux advisories RLSA-2026:64775RLSA-2026:64808

  • kernel Azure Linux 3.0 6.6.145.2-1

azure linux advisories AZL-93875

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-64287 updated cvss 7.0

kernel: KVM: arm64: Bound used_lrs when flushing the pKVM hyp vCPU

  • Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more
    affected: workaround, no fix available, no fix planned “Will not fix”
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-687.45.1.el9_8, perf 5.14.0-687.45.1.el9_8, rtla 5.14.0-687.45.1.el9_8, python3-perf 5.14.0-687.45.1.el9_8, kernel-devel-matched 5.14.0-687.45.1.el9_8, kernel-64k-devel-matched 5.14.0-687.45.1.el9_8, +7 more
    fixed: vendor fix RHSA-2026:64808
  • Red Hat Enterprise Linux AppStream (v. 10) rv 6.12.0-211.52.1.el10_2, perf 6.12.0-211.52.1.el10_2, rtla 6.12.0-211.52.1.el10_2, python3-perf 6.12.0-211.52.1.el10_2, kernel-devel-matched 6.12.0-211.52.1.el10_2, kernel-64k-devel-matched 6.12.0-211.52.1.el10_2, +7 more
    fixed: vendor fix RHSA-2026:64775
  • Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-687.45.1.el9_8, kernel-64k 5.14.0-687.45.1.el9_8, kernel-core 5.14.0-687.45.1.el9_8, kernel-tools 5.14.0-687.45.1.el9_8, kernel-modules 5.14.0-687.45.1.el9_8, kernel-64k-core 5.14.0-687.45.1.el9_8, +27 more
    fixed: vendor fix RHSA-2026:64808
  • Red Hat Enterprise Linux BaseOS (v. 10) kernel 6.12.0-211.52.1.el10_2, kernel-64k 6.12.0-211.52.1.el10_2, kernel-core 6.12.0-211.52.1.el10_2, kernel-tools 6.12.0-211.52.1.el10_2, kernel-modules 6.12.0-211.52.1.el10_2, kernel-64k-core 6.12.0-211.52.1.el10_2, +28 more
    fixed: vendor fix RHSA-2026:64775
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-687.45.1.el9_8, kernel-debuginfo-common-s390x 5.14.0-687.45.1.el9_8, kernel-debuginfo-common-x86_64 5.14.0-687.45.1.el9_8, kernel-debuginfo-common-aarch64 5.14.0-687.45.1.el9_8, kernel-debuginfo-common-ppc64le 5.14.0-687.45.1.el9_8
    fixed: vendor fix RHSA-2026:64808
  • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-211.52.1.el10_2, kernel-debuginfo-common-s390x 6.12.0-211.52.1.el10_2, kernel-debuginfo-common-x86_64 6.12.0-211.52.1.el10_2, kernel-debuginfo-common-aarch64 6.12.0-211.52.1.el10_2, kernel-debuginfo-common-ppc64le 6.12.0-211.52.1.el10_2
    fixed: vendor fix RHSA-2026:64775
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-687.45.1.el9_8, kernel-rt-64k 5.14.0-687.45.1.el9_8, kernel-rt-core 5.14.0-687.45.1.el9_8, kernel-rt-modules 5.14.0-687.45.1.el9_8, kernel-rt-64k-core 5.14.0-687.45.1.el9_8, kernel-rt-debug-core 5.14.0-687.45.1.el9_8, +14 more
    fixed: vendor fix RHSA-2026:64808
show 4 more
  • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt 6.12.0-211.52.1.el10_2, kernel-rt-64k 6.12.0-211.52.1.el10_2, kernel-rt-core 6.12.0-211.52.1.el10_2, kernel-rt-modules 6.12.0-211.52.1.el10_2, kernel-rt-64k-core 6.12.0-211.52.1.el10_2, kernel-rt-debug-core 6.12.0-211.52.1.el10_2, +14 more
    fixed: vendor fix RHSA-2026:64775
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-687.45.1.el9_8, kernel-rt-core 5.14.0-687.45.1.el9_8, kernel-rt-modules 5.14.0-687.45.1.el9_8, kernel-rt-debug-core 5.14.0-687.45.1.el9_8, kernel-rt-modules-core 5.14.0-687.45.1.el9_8, kernel-rt-debug-modules 5.14.0-687.45.1.el9_8, +4 more
    fixed: vendor fix RHSA-2026:64808
  • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt 6.12.0-211.52.1.el10_2, kernel-rt-core 6.12.0-211.52.1.el10_2, kernel-rt-modules 6.12.0-211.52.1.el10_2, kernel-rt-debug-core 6.12.0-211.52.1.el10_2, kernel-rt-modules-core 6.12.0-211.52.1.el10_2, kernel-rt-debug-modules 6.12.0-211.52.1.el10_2, +4 more
    fixed: vendor fix RHSA-2026:64775
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 9 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +12 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
23 d ago

Exploit prediction

0.18% chance of exploitation in the next 30 days, higher than 7% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 8.2 CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

Affected products

  • Linux Linux

Classification

Weakness
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.